Test Links Brain Cells With Silicon Chips.

August 28 2001.

The Washington Post.

Scientists for the first time have linked multiple brain cells with silicon chips to create a part-mechanical, part-living electronic circuit, according to a report in today's issue of the Proceedings of the National Academy of Science.

To construct the partially living electronic circuit, scientists at the Max Planck Institute for Biochemistry in Germany affixed multiple snail neurons onto tiny transistor chips and demonstrated that the cells communicated with each other and with the chips.

The advance is an important step toward a goal that is still more science fiction than science: to develop artificial retinas or prosthetic limbs that are extensions of the human nervous system. The idea is to combine the mechanical abilities of electronic circuits with the extraordinary complexity and intelligence of the human brain. Such combinations of biology and technology might one day help the blind to see and the paralyzed to move objects with their thoughts. It might also help to build computers that are as inventive and adaptable as humans' nervous systems and a generation of robots that might truly deserve to be called intelligent.

Meshing nerve cells with electronics has become a hot new field in science but has long been a staple of science fiction. However, what "Star Trek" accomplished with a stroke of the pen has proved harder in real life.

"The nervous system is quite different than a computer," said Eve Marder, a professor of neuroscience at Brandeis University who studies how the brain adapts to change. "Many functions that are physically separate in a computer are carried out by the same piece of tissue" in the brain and nervous system.

The greatest challenge has been in building the interface between biology and technology. Nerve cells in the brain find each other, strengthen connections and build patterns through complex chemical signaling that is driven in part by the environment. Slice away some neurons and others will replace their function. No one understands how the brain learns to adapt, but it is a sophisticated process.

Silicon chips, on the other hand, can perform specific functions with great reliability and speed but have limited responsiveness to the environment and almost no ability to alter themselves according to need.

Biophysicist Peter Fromherz, one of the researchers, called the test "very primitive, but it's the first time that a neural network was directly interfaced with a silicon chip."